Environmental Characteristics of Desert Tortoise (Gopherus agassizii) Burrow Locations in an Altered Industrial Landscape

– In the Colorado Desert of California, the western distributional limit of the desert tortoise (Gopherus agassizii) occurs in the Whitewater Hills of the southeastern San Bernardino Mountains. Much of the area has been developed for wind energy generation and tortoises often live in association with altered industrial landscapes. Natural habitat in the area was characterized by a sharp transition zone of plant associations including representatives of the Colorado and Mojave Deserts, coastal, and montane ecosystems. We examined the environmental factors associated with the locations of desert tortoise burrows at a site developed for wind energy generation. Measurements were taken at the opening of burrows, including elevation, slope, aspect, and distance to various natural and anthropogenic features of the landscape. We compared this data set with identical measurements for random points that lacked burrows in the same landscape. The analysis demonstrated that desert tortoises within the study area did not randomly select their burrow sites. Desert tortoise burrows were located closer to roads and concrete foundations associated with wind energy turbines and transformers than were random points. The results challenge the paradigm that desert tortoises are negatively affected by all forms of anthropogenic disturbance and suggest that with proper planning, some forms of development in the desert are compatible with conservation of sensitive species.